807 research outputs found

    Role Of Disorder In The Conduction Mechanism In Polyanilines

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    We present the first theoretical calculations of the electronic structure of long (200 rings) linear chains of polyaniline, ranging in composition from leucoemeraldine to emeraldine, allowing for compositional disorder in that the sequence of quinoid-benzenoid groups is random. We show that random protonation of the disordered polymers may induce p-type conductivity: This process pulls the Fermi energy down into the valence band, past localized band tails, to extended states. The effect is only seen if disorder is taken into account. © 1989 The American Physical Society.63778678

    Alterations In The Achilles Tendon After Inflammation In Surrounding Tissue

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    Objective: To analyze the characteristics of the Achilles tendon of rats after induction of localized inflammation in the rat paw. Methods: In our study three groups were used: inflamed group with carrageenan in rat paw (G1); saline group (G2) and control group (G3). After 4 hours the animals were euthanized and the Achilles tendon removed. Results: No significant differences were observed in the analysis of non-collagenous proteins, glycosaminoglycans and hydroxyproline in the groups but a tendency of reduction was verified in G1. As regards the organization of collagen molecules, no differences were observed between groups. With respect to MMPs activity, a stronger presence of the active isoform of MMP-2 in G1 was observed, suggesting that the remodeling was occurring. Conclusion: Thus, we conclude that the inflammatory process in rat paw may affect the remodeling of tendons located near the inflamed site.205266269Maffulli, N., Kader, D., Tendinopathy of tendo Achillis (2002) J Bone Joint Surg Br, 84 (1), pp. 1-8Maffulli, N., Rupture of the Achilles tendon (1999) J Bone Joint Surg Am, 81 (7), pp. 1019-1036Järvinen, T.A., Kannus, P., Maffulli, N., Khan, K.M., Achilles tendon disorders: etiology and epidemiology (2005) Foot Ankle Clin, 10 (2), pp. 255-266Oliveira, F.S., Pinfildi, C.E., Parizoto, N.A., Liebano, R.E., Bossini, P.S., Garcia, E.B., Effect of low level laser therapy (830 nm) with different therapyregimes on the process of tissue repair in partial lesion calcaneous tendon (2009) Lasers Surg Med, 41 (4), pp. 271-276Karousou, E., Ronga, M., Vigetti, D., Passi, A., Maffulli, N., Collagens, proteoglycans, MMP-2, MMP-9 and TIMPs in human Achilles tendon rupture (2008) Clin Orthop Relat Res, 466 (7), pp. 1577-1582Riley, G., Matrix metalloproteinase activities and their relationship with collagen remodelling in tendon pathology (2002) Matrix Biol, 21 (2), pp. 185-195Dario, B.E., Barquilha, G., Marques, R.M., Lesões esportivas: um estudo com atletas de basquetebol Bauruense (2010) Rev Bras Cienc Esporte, 31 (3), pp. 205-215Vieira, C.P., Aro, A.A., Almeida, M.S., de Mello, G.C., Antunes, E., Pimentel, E.R., Effects of acute inflammation induced in the rat paw on the deep digital flexor tendon (2012) Connect Tissue Res, 53 (2), pp. 160-168Tillander, B., Franzén, L.E., Nilsson, E., Norlin, R., Carrageenan-induced subacromial bursitis caused changes in the rat's rotator cuff (2001) J Orthop Res, 19 (3), pp. 441-447Winter, C.A., Risley, E.A., Nuss, G.W., Carrageenin-induced edema in hind paw of the rat as an assay for antiiflammatory drugs (1962) Proc Soc Exp Biol Med, 111, pp. 544-547Bradford, M.M., A rapid and sensitive method for the quantitation of microgram quantities of protein utilizing the principle of protein-dye binding (1976) Anal Biochem, 72, pp. 248-254Farndale, R.W., Buttle, D.J., Barrett, A.J., Improved quantitation and discrimination of sulphated glycosaminoglycans by use of dimethylmethylene blue (1986) Biochim Biophys Acta, 883 (2), pp. 173-177Marqueti, R.C., Parizotto, N.A., Chriguer, R.S., Perez, S.E., Selistre-de-Araujo, H.S.A., ndrogenic-anabolic steroids associated with mechanical loading inhibit matrix metallopeptidase activity and affect the remodeling of the achilles tendon in rats (2006) Am J Sports Med, 34 (8), pp. 1274-1280Vidal, B.C., Mello, M.L., Supramolecular order following binding of the dichroic birefringent sulfonic dye Ponceau SS to collagen fibers (2005) Biopolymers, 78 (3), pp. 121-128Riley, G., Tendinopathy:from basic science to treatment (2008) Nat Clin Pract Rheumatol, 4 (2), pp. 82-89Szabo, K.A., Ablin, R.J., Singhingh, G., Matrix metalloproteinases and the immune response (2004) Clin Appl Immun Rev, 4, pp. 295-319Chakraborti, S., Mandal, M., Das, S., Mandal, A., Chakraborti, T., Regulation of matrix metalloproteinases: an overview (2003) Mol Cell Biochem, 253 (1-2), pp. 269-285Magra, M., Maffulli, N., Matrix metalloproteases: a role in overuse tendinopathies (2005) Br J Sports Med, 39 (11), pp. 789-791Clutterbuck, A.L., Harris, P., Allaway, D., Mobasheri, A., Matrix metalloproteinases in inflammatory pathologies of the horse (2010) Vet J, 183 (1), pp. 27-38Marsolais, D., Duchesne, E., Côté, C.H., Frenette, J., Inflammatory cells do not decrease the ultimate tensile strength of intact tendons in vivo and in vitro: protective role of mechanical loading (2007) J Appl Physiol, 102 (1), pp. 11-1

    Dengue Virus 3 Genotype I in Aedes aegypti Mosquitoes and Eggs, Brazil, 2005–2006

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    Dengue virus type 3 genotype I was detected in Brazil during epidemics in 2002–2004. To confirm this finding, we identified this virus genotype in naturally infected field-caught Aedes aegypti mosquitoes and eggs. Results showed usefulness of virus investigations in vectors as a component of active epidemiologic surveillance

    A Two-Field Quintessence Model

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    We study the dynamics of a quintessence model based on two interacting scalar fields. The model can account for the (recent) accelerated expansion of the Universe suggested by astronomical observations. Acceleration can be permanent or temporary and, for both scenarios, it is possible to obtain suitable values for the cosmological parameters while satisfying the nucleosynthesis constraint on the quintessence energy density. We argue that the model dynamics can be made consistent with a stable zero-energy relaxing supersymmetric vacuum.Comment: 4 pages, 3 eps figures, to be published in Phys. Rev.

    Passatempo Virus, a Vaccinia Virus Strain, Brazil

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    Passatempo virus was isolated during a zoonotic outbreak. Biologic features and molecular characterization of hemagglutinin, thymidine kinase, and vaccinia growth factor genes suggested a vaccinia virus infection, which strengthens the idea of the reemergence and circulation of vaccinia virus in Brazil. Molecular polymorphisms indicated that Passatempo virus is a different isolate

    Propriedades de ZrO2 (Y2 O3) reciclado proveniente da confecção de próteses dentárias

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    RESUMO O objetivo deste trabalho foi a recuperação de descartes de ZrO2(Y2O3) oriundos de laboratórios de próteses dentárias, a partir do seu reprocessamento. Os descartes de ZrO2(Y2O3) foram fragmentados, peneirados e calcinados a 900ºC. Pós com tamanho menor que 32μm foram prensados uniaxialmente a 100MPa e sinterizados em temperaturas entre 1400 e 1600ºC-120min. Análise de difração de raios X realizadas nos materiais calcinados indicaram a presença majoritária da fase ZrO2 tetragonal. Os compactos apresentaram densidade a verde próximo a 47% e as amostras sinterizadas tiveram sua densidade relativa variando entre 83,5% e 95%, para temperaturas de sinterização de 1400 e 1600ºC, respectivamente. Os resultados da análise de difração de raios X indicaram a presença da fase ZrO2 tetragonal, com dureza Vickers e tenacidade máxima obtidos para as amostras sinterizadas a 1600ºC, da ordem de 1100 HV e 5,7 MPa.m1/2 respectivamente

    Hadron Energy Reconstruction for the ATLAS Calorimetry in the Framework of the Non-parametrical Method

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    This paper discusses hadron energy reconstruction for the ATLAS barrel prototype combined calorimeter (consisting of a lead-liquid argon electromagnetic part and an iron-scintillator hadronic part) in the framework of the non-parametrical method. The non-parametrical method utilizes only the known e/he/h ratios and the electron calibration constants and does not require the determination of any parameters by a minimization technique. Thus, this technique lends itself to an easy use in a first level trigger. The reconstructed mean values of the hadron energies are within ±1\pm 1% of the true values and the fractional energy resolution is [(58±3)/E+(2.5±0.3)[(58\pm3)% /\sqrt{E}+(2.5\pm0.3)%]\oplus (1.7\pm0.2)/E. The value of the e/he/h ratio obtained for the electromagnetic compartment of the combined calorimeter is 1.74±0.041.74\pm0.04 and agrees with the prediction that e/h>1.7e/h > 1.7 for this electromagnetic calorimeter. Results of a study of the longitudinal hadronic shower development are also presented. The data have been taken in the H8 beam line of the CERN SPS using pions of energies from 10 to 300 GeV.Comment: 33 pages, 13 figures, Will be published in NIM
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